Hydrogen sulfide (H2S, or “sour gas”) is one of the most lethal hazards on oil tankers and offshore vessels. It is colorless. At low concentrations, it smells like rotten eggs. At higher concentrations, it deadens your sense of smell entirely, which means by the time you can’t smell it anymore, you may already be in serious danger.
Workers on oil tankers, crude carriers, and vessels handling sour crude are exposed to this risk regularly. When operators fail to monitor for it, provide adequate respiratory protection, or train crew members properly, people get seriously hurt or don’t make it home at all.
Where Sour Gas Comes From on a Tanker
Sour crude oil contains sulfur compounds that release hydrogen sulfide gas during loading, unloading, tank cleaning, and cargo transfer operations. Enclosed or semi-enclosed spaces like cargo tanks, pump rooms, void spaces, and cofferdam areas are where concentrations build to dangerous levels fastest.
The risk is highest during:
- Tank entry for inspection or cleaning
- Cargo loading and discharge operations
- Ballasting and deballasting near cargo spaces
- Any hot work performed near cargo tanks
At low concentrations, H2S causes eye and respiratory irritation. At moderate levels, it causes headaches, dizziness, and nausea. At high concentrations it causes loss of consciousness within seconds and death within minutes. Workers have died in tank spaces before anyone on deck realized something was wrong.
The Injuries Sour Gas Exposure Causes
Workers who survive significant H2S exposure often face long-term health consequences that go well beyond what a company doctor acknowledges after an initial evaluation:
- Pulmonary damage and chronic respiratory problems
- Neurological effects including memory loss, cognitive impairment, and difficulty concentrating
- Eye damage ranging from irritation to permanent vision loss
- Cardiovascular effects from oxygen deprivation during acute exposure
- Psychological trauma, including anxiety and PTSD, particularly in workers who lost consciousness or witnessed a coworker collapse
These injuries can take weeks or months to fully manifest. Workers who were exposed but felt well enough to return to duty may not realize the full extent of the damage until well after the incident.
Operator Negligence in Sour Gas Cases
H2S exposure on oil tankers is preventable. Operators are required to monitor air quality in confined spaces before entry, provide appropriate respiratory protection, train crew members to recognize symptoms and respond to alarms, and maintain gas detection equipment in working order.
When those requirements are ignored, that is negligence. Common failures in sour gas injury cases include:
- Sending workers into tank spaces without prior atmospheric testing
- Faulty or uncalibrated gas detection equipment
- Failure to provide or require the use of supplied-air respirators during tank entry
- Inadequate training on H2S hazards and emergency response
- No standby rescue personnel during confined space entry
Your Legal Rights After a Sour Gas Exposure
If you’re a seaman exposed to sour gas on an oil tanker or offshore vessel, the Jones Act protects your right to pursue a negligence claim against your employer. If gas detection equipment failed or wasn’t maintained, you may also have an unseaworthiness claim against the vessel owner.
You are entitled to maintenance and cure from the date of your injury, covering your living expenses and all reasonable medical costs. Given the delayed and long-term nature of H2S injuries, make sure your cure benefits remain in place until you have a complete picture of your medical condition, not just until a company doctor signs off.
Exposed to Sour Gas on a Vessel? Call Us.
H2S cases require attorneys who understand both the medical and maritime dimensions of the injury. If you were exposed to sour gas on an oil tanker or offshore vessel along the Gulf Coast,
The Maritime Injury Law Firm is ready to fight for you. Contact us today for a free, confidential consultation.
